A prospective survey was conducted among anaesthesiologists to determine their criteria for excluding a patient from autologous blood donation prior to total hip prosthesis. Information on patients operated on during a 5-week period was obtained using a questionnaire, consisting of a set of possible responses to simple questions, matched with some parametric values. Sixty-eight of the 99 patients included in the survey underwent surgery without donation. Age was the main cause for exclusion (34%). The age of patients excluded because of their age alone was 75 +/- 11 years (standard deviation). The age of patients excluded from donation and who did not subsequently receive homologous blood was comparable with that of patients not autotransfused but who received homologous blood (68 +/- 4 vs. 69 +/- 6 years, respectively). Post-operative haemoglobin concentrations were similar whether transfusion was performed or not, and regardless of the origin of blood given. Since age is no longer taken into consideration at the time of transfusion, it is likely that exclusion of a patient from autologous blood donation because of age is an arbitrary choice.